1. Field of the Invention
This invention relates to a portable device for anchoring umbrellas, flags and other articles that include a pole or shaft that requires support.
2. Description of Related Art
There are a number of devices in the prior art that serve as anchoring devices for beach umbrellas, volleyball net supports and the like. The present invention is most closely associated with a group that is characterized by the use of sand or other native material to provide ballast for stabilizing the anchor device.
U.S. Pat. No. 4,753,411 discloses a Portable Beach Umbrella Safety Base that comprises two semicircular plates that provide a surface upon which sand can be placed to provide weight to assist in anchoring the device. The semicircular plates are flat, rigid objects that are limited as to the amount of sand or other material that can be supported due to the lack of any sidewalls or other peripheral containment. Although the capacity of the plates can be increased by increasing the size of the plates, this increase comes at the expense of greater weight and inconvenience of handling and storage.
U.S. Pat. No. 5,452,877 discloses a Beach Umbrella Anchor Bag that comprises a flexible enclosure with a relatively narrow opening that surrounds the shaft of a beach umbrella when in use. Although this device has the advantage of being able to accept a greater amount of sand as ballast when compared to the flat plates of the Portable Beach Umbrella Safety Base, the narrow opening limits the size of rocks or other objects that could also be used as ballast materials.
Both of the above described devices are discrete devices that are not integrated with the umbrellas that they are used to support or anchor, nor are they well adapted to streamlined integration with an umbrella shaft. Existing ballast-type devices for anchoring beach umbrellas are also limited in the types of material that can be used as ballast with a particular device.